The present invention relates to footwear, and in particular to systems and methods used to fit footwear, e.g., shoes, to a wearer.
Prior to the Industrial Revolution and the advent of mass production, shoemaking was necessarily a labor intensive manual process requiring a skilled shoemaker, i.e., a cobbler. The basic process by which a cobbler would fit a shoe involved taking measurements of a wearer's foot, altering the shape and size of a standard size last to correspond to the measurements (e.g., by tacking material such as leather or putty onto the last), then forming the shoe upper and sole about the modified last. The traditional manual shoemaking technique is capable of producing a close custom fit. However, manual shoemaking requires a high degree of skill to produce a good result; it is also labor intensive and costly.
Today, of course, most shoes are manufactured in factories in mass quantities and shipped to stores that stock each shoe in standard sizes. At the store, the length and width of the wearer's foot is measured to determine a nominal foot size. This is typically performed with a conventional Brannock shoe measurement tray. Such devices measure the length of the foot in half size increments, e.g., from size 1 to size 151/2. Each half size increment is equal to 1/6". Width designations are provided on a scale of letters incremented by 1/6, e.g., AAA, AA, A, B, C, D, E, EE, and EEE. Once the wearer's foot has been measured to determine a nominal size, the wearer will try on the desired shoe style in the measured length and width. If it is comfortable and seems to fit well, that size will be chosen. If it does not fit quite right, often other lengths and widths close to the measured length and width will be tried on to see if a better fit can be obtained.
A problem arises due to the fact that the standard 1/6" increments of length and width are not fine enough to provide all wearers with a good fit. Additionally, often shoe stores will not have in stock, or even carry, all of the standard shoe sizes, i.e., combinations of standard shoe lengths and widths. In particular, it is common for shoe stores to reduce their inventory by carrying only a few widths for each length, and by carrying large sizes, e.g., size 14 length and above, in only full size increments. In such cases, the wearer can only choose the in-stock shoe that comes the closest to his/her size, i.e., the shoe that fits the best of the available choices. Moreover, shoes are conventionally sold in matched pairs, despite the fact that many persons have left and right feet differing by a half size or more in length and/or width. As a result, the conventional fitting technique provides an approximated fit that is typically less than ideal. A better fit could be obtained if footwear was offered in length increments finer than the present 1/6" increments, if stores could be counted on to carry all of the different standard lengths and widths, and if shoes were available in other than matched pairs. However, to offer such a range of sizes requires manufacturers to make, and retailers to stock, a very large number of shoes. This can result in substantial additional carrying costs and losses due to unsold stock, and may limit a store as to the types and styles of shoes that it can afford to offer.
In an effort to provide a better fit than is typically provided by the above standard fitting technique, without the necessity of increasing shoe stock, numerous approaches have been proposed for providing so-called custom fitted footwear. One approach involves the in-situ molding of the interior of a stock shoe in the shape of a wearer's foot. See, e.g., Dubner U.S. Pat. No. 2,794,270, Robinson U.S. Pat. No. 3,325,919, von den Benken U.S. Pat. No. 3,641,688, Dawber U.S. Pat. No. 4,428,089, and Pols et al. U.S. Pat. No. 4,463,761. Such methods generally require expensive equipment and footwear designs. Moreover, the in-situ molding of such systems requires that the wearer's foot be used as a mold form. This can be an unpleasant and time consuming process, e.g., many of the molding methods involve the injection of moldable (sometimes chemically reactive) material around the foot and/or the application of heat to the material surrounding the foot.
A further problem with in-situ shoe molding techniques is that they are generally limited to the formation of a shoe interior having a form corresponding directly to the shape of the foot. Such a close correspondence of shape may not result in the best fit for all wearers. For example, some wearers may prefer a relatively loose fit over a snug form-fit. Or, differences between the shoe interior shape and the wearer's foot may be desirable to compensate for foot problems, e.g., flat feet or tendencies to over-pronate or supinate. If after a custom footwear forming process is completed (based on a direct mold of the wearer's foot, or solely on measurements of the foot) the footwear is not comfortable to the user, the substantial time, effort and expense for performing the custom forming operation will have been wasted.
Another known approach for custom fitting footwear involves the selective placement of appropriately chosen shoe inserts. Such inserts may, e.g., be stock inserts adapted to better accommodate different foot girths, as disclosed in Otsuka U.S. Pat. No. 4,897,938. A fitting method involving the selection of an appropriate insert from a collection of stock inserts affords a degree of customization without increasing the number of shoe sizes that the retailer must stock. However, the retailer must maintain a stock of inserts of different types and sizes in addition to his normal shoe inventory.
Shoe inserts may also comprise moldable material and be designed from an impression of the wearer's foot. See, e.g., Phillips U.S. Pat. No. 4,510,636, Irwin et al. U.S. Pat. No. 4,520,581, DeBettignies U.S. Pat. No. 4,868,945 and Lyden U.S. Pat. Nos. 5,203,793; 5,101,580 and 4,674,206. This type of system requires that material be molded using the wearer's foot as a form, and thus has the disadvantages mentioned in connection with the in-situ shoe molding techniques mentioned above.